Circuit controlling instrument



1943- H. G. WITMER CIRCUIT CONTROLLING INSTRUMENT Filed May 25, 1942 invention will become proceeds.

Patented Aug. 17, 1943 omom'r CONTROLLIVNGINSTRUMENT Harold G. VVitmer, Edgewood, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania.

Application May 2-5, 1942, Serial No. 444,382

3 Claims.

My invention relates to circuit controlling struments, and particularly to circuit controlling instruments which are effective to modify the condition of an electric circuit in response to shock or vibration transmitted to the instrument.

More particularly, my invention relates to circuit controlling instruments which are adapted for mounting on a railway trackrail, and which respond to vibrations imparted to the rail by passing trains, for the purpose of visibly or audibly announcing the approach oia train at sta-M,

tions, crossings, or otherdistant points along the line, through the instrumentality of a signaling device controlled by an electric circuit in which the instrument is included.

One object of my invention is to provide an instrument of the type described employing a J mercury contact, and having improved means for holding the contact and also for adjusting the immersion of the electrodes in the mercury of the contact to control the sensitivity. of the inestrument.

Instruments embodyin my present invention are an improvement upon those described in my a prior Patent No, 2,076,928, granted on April 13,

' nesses According to, my invention, a heavy plate is rigidly fastened at one end to a track rail by means of clampsand a somewhat thinner plate a is rigidly fastened at one end to this heavy plate.

A reed assembly consisting of a reed provided at adjustable means which permits it to be rocked about its pivot to obtain within limits any desired-degree of immersion of the electrodes of the mercury contact. When a train passes" over the rail to which the instrument is attached, the two plates and the reed are all set into vibration, but

due to their different stifinesses they vibrate at different frequencies which amplifies the movement of the mercury contact carried by the reed. The movement of the mercury contact momentarily opens any circuit in which it is included.

Other objects and characteristic features of my apparent as the description I shall describe one form of instrument em- In the accompanying drawing, Fig. 1 is a view showing a track rail in transverse section with a track instrument embodying my invention attached thereto, the cover of the instrument being shown in section to better illustrat the remaining parts. Fig. 2 is a top plan view with the cover removed of the instrument shown in Fig. 1. 1 Similar reference characters refer to similar parts in both views.

Referring to. the drawing, the instrument in the form here shOWIl comprises a heavy rectangular supporting plate I which is securely fastened at one end to the base of a railway track rail 2 by means of clamps 3 and 4 and studs or bolts 5.

The one clamp 3 directly engages the upper side of the base flange, while the other clamp 4 overlies the base flange with some clearance and is threaded for the reception of set screws 6 which are screwed into engagement with the upper side of the base flange, whereby the supporting plate may be readily secured to, rails of different weights having base flanges of diiierent thick- The set screws 6 are arranged to be locked in place by means of lock nutsv 6a in the usual and well-known manner.

A second plate I, which is considerably thinner and somewhat narrower than the supporting plate I, is rigidly fastened at one end to the supporting plate I intermediate its ends bvmeans of four screws 8 which extend downwardly through clearance holes in the plate 1 and in a spacing .block 9, and are screwed into tapped holes l0 formed inthe plate I. v

Secured to the plate I at its opposite sides adjacent its rigid end are two vertically extending spaced parallel uprights II and I2 provided with aligned holes I3 and I4. These holes receive with some clearance a pivot pin l5 which pivotally supports the lower one of three superposed blocks l6, l1 and 18. These blocks are rigidly fastened together by means of screws 19, and clamped between'the' lowertwo blocks l5 and l! is a reed The upper block I8 projects out over the reed 20 in vertically spaced relation for some distance and is provided adjacent it outer end with an adjustable stop screw 2| which engages the reed intermediate its ends for a purpose which will appear presently. The stop screw is arranged to be locked in an adjusted position by means of a jam nut Zia.

The reed 20 at its free end is provided with a clipzlwhich supports amercury contact. This contact may have any preferred construction,

'and as here shown comprises a glass envelope 23 containing a pool of mercury 24 and two electrodes 25 and 26 which at times make contact with the'mercury. Flexible lcadsZ's and 23 ex- I 'The"1c '1 ates T and aiiiparts carried therebyf iare m li y Web a Pre ent l t o be va ed' within'lirilitshy meansici the adjusting screw '21 as"i'sobvious.

tend from the eleetrodes 25 and 26 and are secured at their lower ends to terminal posts 29 and 38; The terminal posts 29 and 3%) are moulded into the upper ends of insulating supports 3! seconnec'ted y rneans oi strap c l nectors 33, and

34 with other terminal postsfiifa'hd These latter terminal posts are similar to the terminal posts 29 and 39, andare secured to the plate 7 in the same manner as the terminalfppsts -gfi and so;

Attached to the'terminal posts 35 and BQ a re i lead-in Wires 3? and 38 o acne aligned clearance holes iii andh pro deal plates i and through eff;

32 which is clamped to theundersides of the plate'i. IA rubber grommet 1E3 surrounds "wires 3? r and '38 where they pass through "the hole,- Mfto qseal this oponing against the entry of moisture.

- It .is desirab e t gh la ia a shaman; h

.ae ree pr m e sion, o t e ect o s in the pool offn'iercu yto' assistin controlling .tne'sensitivity of the d Vice; to vi'p; s: pu p se one-upr h t 2 "at on, for

than the other upright anctisilh its upperjend with a transvelSfi slot ceives. xvi-ti some yclearam 'g I 'lateraily' pro'J'ecting :pin, e55 secured tofthelilolck t8. Two screws 6?, and G8 mountedin tapped hole-sla and provided in;theupright 2 ft'end into the slot. 45 on opposite sides'oi the pin 'tpand cooperate-therewith in such manner that I 'by screwing thejone screw inand hacking-the otherscrewoutith'e assembly-comprising the read and contactand the associated blocks i 5'5, ii and change the degreeof'immersion' ofthejelectrodes "'25 and zeta the 'poolioi mercury 2 2.

their "adjusted positions, by hieafis' or 5am: nuts' 5! and Ef'nixounted oh-fthe enclosed within 'a cov'er 'ss fhei -in place'by studs 2 A 'gasketifit'a 'of cork or thlike 'isinterposed 1 between the cover-andthefsupporting}plate! to firevent dirt, moisture or "other foreign i'subr stances fro c'hiii'g the ericlo'sedpa'rts.

ted 2B are alls'e't into "vibration, ibut fall'vihrateatfdiiiere frequencies.- 'Theidifier-o- I ji l "e' nt f'ri'equ en'cies "of Vibration cause es which e 'iifercury contact.

lent of I I he fpartsfare so adjiisted that when the rail is not 'vilgrati i; e cury contact will he 'irrlr ri ersedim the pool "of mercury, and 'when the contact isvibr'ated,

th 'vi dnr au I cs e pool t'o momentarily the-amountbi 'initiar tension m' th'e reed 'This"t'ensionfcan In actual practice an nstrument embodying thescope of the a-ppended 93a iigid plateprovided atone end with 'Th'escrews I I tyjof thew 'devicede ends'toso'meextent-upon the stiffness 'poses. For example, it may 'be used to control highway crossingsignals in the manner shown in Letters Patent of the United States No;

' 2,091,687 granted to Bernard E. O-Hagan and- 5 myself on August 31, 1937,vfor Apparatus for the cured at tl i eir lower ends to the plate '3, and are I control o f highway crossing signals, in which eventfit would "be used laiieo'f 'the instru- 'nierits M I and M2 shown in said'patent.

N I One advantage of an instrument embodying my inventionis that it can be readily mounted on 'Alii'hOil'ghIhave'herein shown and described only one form of instrument embodying my; "invention, it is understood that various changes -'andiifiodifications nlay he made "ingfrom thespirit and s cope o 'rny invc Having thus; described my invention, what I Claimis: I II 'A'c'lrbuit controlling instru clamping it toa Tailway' track i'ail subject d to j-yiloration as. a vehiclepasses' there'ove r, 3 se ohd plateclessrigid than-said firstpla-tecla pejdjat 'oneierrd to said first plate intermediate gs ends ei i a 'f'se'cond'plate f-ree t'oolvibra-ta 'ap I I hlc'clzs'pivotally attached' to said Second plate for limited pivotal movementaoouta ghorizontai ineans iorfclampin'g said hlocks in an adjusted I fixed'position witlr-respect'to said secondplate, a fiee'd'clampedatone end between said-blccksand mercury-contact"secured to the free" "reed. v l. 7 1 v 2; T'A circuit' tontrolling "instrument comprising arigidplate provided at one end wlth meahs fop I "lamping"it"td'a"railwaf track rail which is-ati I l1 in es "subjected to' vibratiori loy passing vehicles, 'secohd' plat'e'jiigidlyfastened atoneend to-said diateits ends, said secondplate 7'5 uprights by means of a pivot pin passing through I "the parts i can be made tolwork with equal s'c-ms1 lvityat' alliocations.

I in within the lower block, a laterally projecting pin mounted in the upper block and extending with clearance into said slot, screws screwed through said one upright and projecting at their ends into said slot and cooperating with said laterally projecting pin on opposite sides thereof to enable said blocks to be rotated to and locked in an adjusted position with respect to said second plate, a reed 5 third screw adjustably screwed through said upper block and cooperating with said reed intermediate its ends to control its sensitivity to vibration.

HAROLD G. WITMER. 

